Listen to Robert Emmerich introduce The Big Apple, a hit song from 1937. Music written by Bob and performed by Tommy Dorsey's Clambake Seven with Bob on piano. Lyrics written by Buddy Bernier and sung by Edythe Wright. Audio provided by Dorothy Emmerich.

“It takes nine months to make a baby, no matter how many people you put on the job”

"It takes nine months to make a baby, no matter how many people you put on the job” is a popular American business proverb. For some businesses, such as apple-picking in an orchard, hiring more people can make the work finish faster. For other businesses, such as computer programming, hiring more people may, in fact, make the work finish more slowly. The saying means that some processes just take a certain amount of time to complete.

William S. Knudsen (1879-1948) was in charge of the War Production Board during World War II. Knudsen, upon being asked in 1941 if he could speed things up, reportedly responded with the childbirth analogy “No matter how many men you put on the job, it still takes nine months to produce a baby.”

“When a task cannot be partitioned because of sequential constraints, the application of more effort has no effect on the schedule. The bearing of a child takes nine months, no matter how many women are assigned. Many software tasks have this characteristic because of the sequential nature of debugging.”

Wikipedia: William S. KnudsenWilliam Signius Knudsen (March 25, 1879 – April 27, 1948) was a leading automotive industry executive. His experience and success as a key senior manager in the operations sides of Ford Motor Company and later General Motors led the Franklin Roosevelt Administration to commission him as a Lieutenant General in the United States Army to help lead the United States’ war materiel production efforts for World War II.
(...)
In 1940, President Roosevelt asked Knudsen to come to Washington to help with war production. In January 1942, Knudsen was commissioned a Lieutenant General in the U.S. Army, the only civilian ever to join the Army at such a high initial rank. He worked as a consultant and troubleshooter for the War Department. He was appointed Director of the Air Technical Service Command when it was founded in July 1944 and served in the Army until June 1, 1945.

Wikiquote: Theodore von KármánTheodore von Kármán (von Sköllöskislaki Kármán Tódor) (11 May 1881 – 6 May 1963) was a Hungarian-born engineer and physicist who was active primarily in the fields of aeronautics during the seminal era in the 1940s and 1950s. He is personally responsible for many key advances in aerodynamics, notably his work on supersonic and hypersonic airflow characterization.

Sourced
Everyone knows it takes a woman nine months to have a baby. But you Americans think if you get nine women pregnant, you can have a baby in a month.
, November 1957 - Told to Joseph G. Martin, then Aide-de-Camp to Maj. Gen. Daniel E. Hooks, as Lt. Martin escorted Dr. von Kármán from New York City to lead a secret symposium on space flight in Cloudcroft, NM. Sputnik had been launched a month before and every branch of the US military had a separate space program and were desperately trying to get off a successful launch.

Google BooksBroadcast
Issues 315-351
1941
Pg. 8:
I want to say once more, as I recall it was Bill Knudsen, you remember, back — of General Motors, was head of the OPM. What he said was that nobody has yet found a way of making a baby in less than nine months. That’s an extremely important truth. You’ve got to prepare the ground and put in the seed before you can get a crop and it takes months and months to get there and all of the straining in the world isn’t going to make any difference. It takes months and months to put an industrial machine such as ours is, employing fifty to sixty million people, half of whose production has gone to war and all of whose production must now go to peace, it takes time to get that moving and I insist that the record of performance by this people of ours has been miraculous in war and is miraculous in peace.

Google BooksAdvertising & Selling
Volume 35, Issues 1-6
1942
Pg. 69:
America’s business today is War. A year ago it was Defense...or nearly so. True, in January 1941 the President’s 50000-plane speech was seven months old, but Lend-lease, for example, was still two months away. OPM was only in its first month. Monthly plane production was in the low hundreds. And new business-words like ‘priority’ and ‘sub-contracting’ and ‘allocation’ were still new. The huge machine had not yet started rolling. Tooling-up was taking tooling-up time. Director Knudsen said, “No matter what you do...it still takes nine months to have a baby.”

26 August 1950, Springfield (MA) Union, “Learning Slowly is Best,” pg. 22, cols. 6-7:
When William S. Knudsen was head of the War Production Board, he was challenged by a House Committee to show that reasonable progress was being made on national defense. He answered, “It’s like this. Despite your modern hospitals and anesthetics, despite your obstetricians and psychiatrists, despite all your achievements in research, medicine, and science—it still takes nine months to have a baby.”

There are some things that just can’t be rushed. Efficient learning is one of them. Small doses taken at well-interspersed intervals is the best rule.—William A. Rossi in Your Life.

27 May 1951, The Oregonian (Portland, OR), “U.S. Speeds Arms Output; Waits Civilian Pinch Eleven Months After Outbreak of War in Korea” by Sterling F. Green (AP), pg. 6, col. 3:
Officials quote William S. Knudsen, the first production boss in World War II: “Do what you will, it still takes nine months to make a baby.”

Google BooksAmerican Aviation
Volume 16
1952
Pg. 2:
During World War II, the late William S. Knudsen was frequently asked why plane production could not be speeded up by putting more men on the project. Knudsen’s reply was an analogy on childbirth: “No matter how many men you put on the job, it still takes nine months to produce a baby.”

11 March 1959, Dallas (TX) Morning News, “Marcus Calls ‘Sack’ Greatest Fiasco in Modern Fashions,” sec. 3. pg. 1, col. 3:
The defeat came “because we in the fashion business forgot that just as it takes nine months to make a baby, and considerably longer, I’m informed, to make an elephant, as does it take time for the gestation period of a fashion.”
(Stanley Marcus of Neiman-Marcus stores—ed.)

Google BooksThe West Point Conference on Latin American Problems: [final report].
Edited by Jess P. Unger
West Point, NY: United States Military Academy
1964
Pg. 102:
Bill Knudsen in the early part of World War II pointed out that, with all the advances of science, it still takes nine months to make a baby. He might have added that with all the advances of science and, indeed, partly because of the advances of science, no one has yet figured out any way to produce a really trained human being in less than about 25 years.

Google BooksThe Mythical Man-Month:
Essays on Software Engineering
By Frederick Phillips Brooks
Reading, MA: Addison-Wesley Pub. Co.
1975
Pg. 17:
Men
When a task cannot be partitioned because of sequential constraints, the application of more effort has no effect on the schedule. The bearing of a child takes nine months, no matter how many women are assigned. Many software tasks have this characteristic because of the sequential nature of debugging.

Google BooksAn Information Systems Manifesto
By James Martin
Carnforth, Lancashire: Prentice-Hall
1983
Pg. 190:
Fred Brooks, in his book The Mythical Man-Month, stresses that men and months are interchangeable commodities only when a task can be partitioned among many workers with no communication among them. This is true of picking oranges or painting a battleship; it is far from true of large conventional programming projects.

When a task cannot be partitioned because of sequential constraints, adding more manpower would have no effect on the completion time. Having a baby takes nine months no matter how many women are assigned.

Google BooksThe Entrepreneurial College President
By James L. Fisher and James V. Koch
Westport, CT: Praeger Publishers
2004
Pg. 24:
Further, some activities require patient cultivation and cannot be rushed. As a cautious management expert once noted, it takes nine months to make a baby, no matter how many people one puts on the job.

Google BooksDreaming in Code:
Two Dozen Programmers, Three Years, 4,732 Bugs, and One Quest for Transcendent Software
By Scott Rosenberg
New York, NY: Three Rivers Press
2007
Pg. 218:
Brooks’s Law will kick in.

“That’s true,” Kapor admits. “It’s the old ‘It takes nine months to make a baby, no matter what’ principle.”

Google BooksGuiding Professional Learning Communities:
Inspiration, Challenge, Surprise, and Meaning
By Shirley M. Hord, James L. Roussin and William A. Sommers
Thousand Oaks, CA: Corwin
2010
Pg. 95:
It takes nine months to make a baby, no matter how many people you put on the job. — American saying

WWVB: What Would Vannevar Blog?
April 30, 2010
The Mythical Man-Month
(...)
Sometimes Fred Brook’s insight applies to physical projects as well as to intellectual or social projects. He famously said, “it takes nine months to make a baby, no matter how many women you put on the project”.

Bloomberg NewsOxford Nanopore To Sell Tiny DNA Sequencer
By Kristen Hallam on February 17, 2012
(...)
‘Pregnant Woman’
“Our competitors are like a pregnant woman,” said Zoe McDougall, a company spokeswoman. “It takes nine months to make a baby, and you can’t put nine women on it and get a baby in a month. With our system, you can put nine women on it and make a baby in a month.”